The objective of this application is to train physicians in surgical, radiation, medical or pediatric oncology as clinical researchers who are adept at translating basic laboratory research in cellular and molecular biology of cancer or cancer immunology into well-designed clinical trials. A total of 7 persons (2 entering in each of the first 2 years, 1 each in years 3, 4 and 5) will be trained under this program. Physicians will learn fundamentals of basic research (Phase I, requiring 1 or 2 years, based on amount of previous lab experience) and then develop protocols in clinical research (Phase II, lasting 2 years). Training will take place in research labs in the Departments of Biochemistry, Chemistry, Biological Structure, Pathology, Radiation Oncology and Medicine, and clinics of the Cancer Center at the-University of Washington School of Medicine and at Fred Hutchinson Cancer Research Center. Additional elements of training, specific to this program, are (1) the requirement for paired mentors (one basic scientist, one clinical investigator) throughout training; (2) didactics in Research Proposal Writing and Grantsmanship and Grant Writing, developed specifically for these trainees, and (3) requirements for writing an R01-type proposal, based on Phase I preliminary data and favorably evaluated by a mock Study Section, in order to pass from Phase I to Phase II. Trainees will be selected from nationwide recruitment of individuals finishing their training in the above oncologic specialties and having outstanding academic qualifications plus some prior activity indicating commitment to research. From the beginning, trainees will plan their research program with both mentors. Mentors and the Executive Committee will evaluate each trainee's progress. The Executive Committee also will be responsible for annual evaluations of this program, which will stress specific accomplishments of each trainee, and for managing the interactions of this training program with ongoing T32 oncology training programs at the University of Washington and the Fred Hutchinson Cancer Research Center.